<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			*{
				margin: 0;
				padding: 0;
				border: 0;
			}
			div{
				background-color: #00FFFF;
			}
			span{
				display: inline-block;
			}
		</style>
	</head>
	<body>
		<div><span></span></div>
		<script type="text/javascript">
			console.log(document.querySelector("span").offsetHeight);//0
		</script>
	</body>
</html>
